Not quite. Code that *wasn't* using either of the two modern APIs for MySQL was "broken".
They removed the oldest, jankiest of the three APIs for connecting to MySQL in php7.
MySQLi (literally, "MySQL Improved" extension) was introduced with PHP 5.0, in 2004.
PDO was introduced with PHP 5.1 in 2005.
The documentation started showing "soft deprecation" notices on mysql_* functions in 2012. It was already common practice to advise people to upgrade to either mysqli or PDO.
The old mysql extension was deprecated as of php5.5, in 2013.
The final shipped version with the mysql extension was 5.6, which was supported until 2018 - half a decade after the deprecation was added.